The present invention relates to refueling systems for motor vehicles, and, more specifically, to a capless refueling assembly at the end of a filler tube for a fuel system, which assembly opens and closes automatically upon insertion and removal of a fuel dispensing nozzle.
Vehicle fuel supply systems commonly include a fuel tank and a filler tube through which fuel is dispensed into the tank. A removable cap is provided at the end of the filler tube, to close the tube. Heat, movement of the vehicle and the like can cause a build-up of vapor pressure in the fuel tank. Under some conditions, vapor and/or fuel droplets can be discharged from the neck of the filler tube, as the cap is removed from the end of the filler tube. In addition to the unpleasant side affects from being sprayed with fuel and/or vapor, a person can be placed in danger from fire or explosion of the highly volatile substances.
It is known to provide a primary fuel shut-off valve near the end of the filler tube, to vent vapors that accumulate in the tank. The primary fuel shut-off valve also functions to limit back flow of fuel into the outermost area of the filler tube, if the fuel sloshes up the filler tube during operation of the vehicle. A removable fuel cap commonly covers the end of the filler tube, and the cap provides a barrier against dirt or other contaminants from reaching the primary fuel shut-off valve and fouling the operation thereof.
Several problems have been experienced with known designs of refueling systems. Fuel caps can be lost, and the replacement thereof is often forgotten after refueling is complete. To prevent loss of the cap, it is known to attach the fuel cap to the vehicle using a flexible tether strap secured to the housing surrounding the filler tube. To ensure that the tether strap remains in the housing and does not interfere with a door closing the housing, the straps used in the past have been relatively short, and some individuals find the strap to be awkward and interfering as the fuel cap is replaced. Further, the nature of such straps has been such as to require the strap and cap to be held out of the way with one hand while the refueling nozzle is inserted into the filler tube with the other hand.
While a tether strap may prevent loss of the cap, it does not ensure that the cap will be replaced each time refueling is completed. Without replacement of the cap, or with improper replacement of the cap, the closure system is not complete. Dirt and contaminants can enter the filler tube, potentially fouling the primary fuel shut-off valve, and interfering with proper operation and function of the valve. It is also possible for the tether strap to fail, resulting in an unconnected cap, and again raising the potential for the cap to be lost or forgotten during a refueling procedure.
Capless systems have been proposed in the past. Many such systems are complex and costly. Some are confusing and difficult to use, requiring training or instruction in the proper use thereof. Others may not protect adequately the intricate parts of the refueling system from dust or grime that will interfere with proper operation.
Another problem associated with refueling assemblies of vehicle fuel systems involves the accumulation of liquids in the housing surrounding the end of the filler tube. Many embody a cavity or chamber in which the end of the tube and the fuel cap are disposed. Water from rain, melting snow and vehicle washing can accumulate in the chamber. Small amounts of fuel can drip from a fuel-dispensing nozzle during a refueling operation, as the nozzle is removed from the filler tube. The fuel can attract dust and grime, which accumulate over time. During hand washing, it is common for water to be sprayed from a hose or pressure washer into the chamber, in an effort to clean the chamber. The accumulation of water in the chamber, from any source, can enter the filler tube, particularly if the cap is removed therefrom for refueling, or at any time if the cap has been lost or not properly and tightly closed on the end of the filler tube.
The present invention is directed to overcoming one or more of the problems identified above by providing a capless refueling assembly that is simple and intuitive to use, operates in conjunction with common primary fuel shut-off valves, and limits the accumulation of water in the housing chamber surrounding the end of the filler tube.
The present invention provides a closure mechanism for the end of a fuel system filler tube, which opens and closes as a refueling nozzle is inserted or removed, and which channels away any liquids that may accumulate near the filler tube end.
In one aspect thereof, the invention provides a capless refueling assembly with a filler tube for receiving an input of fuel at a distal end of the tube. A housing defines a chamber surrounding the filler tube end. An end closure mechanism at the tube end yields to pressure from a dispenser nozzle for opening access to the filler tube, allowing insertion of the nozzle into the filler tube. A drain in the chamber directs liquids away from the filler tube.
In another aspect, the invention provides a capless refueling assembly for receiving fuel from a refueling system having a dispenser nozzle. The assembly has a filler tube for receiving an input of fuel. A housing defines a chamber surrounding an end of the filler tube. A drain in the housing conducts accumulated liquid out of the chamber. An arm is attached to the chamber about a pivot, and an enlargement at an end of the arm covers the filler tube end. A stop cooperates with the enlargement to position the enlargement over the filler tube end. A spring biases the enlargement against the stop. Channels extend through the enlargement for channeling liquid away from the filler tube end and into the chamber.
In yet another aspect thereof, the invention provides a filler tube end closure mechanism for a vehicle fuel system having a filler tube with a distal end adapted to receive a dispensing nozzle of a refueling system. The closure mechanism has an arm rotatable about a pivotal connection. An enlargement on the arm covers the filler tube distal end. A fixed stop engages the enlargement to position the enlargement over the filler tube distal end. A biasing means urges the enlargement against the stop. The enlargement is adapted and arranged to yield to insertion of the nozzle, and the arm is adapted to rotate about the pivotal connection in response to insertion and removal of the nozzle relative to the filler tube.
An advantage of the present invention is providing a closure mechanism for the end of a fuel system filler tube for which the proper use is intuitive, which opens readily in response to the start of a refueling procedure, and which closes automatically upon completion of refueling.
Another advantage of the present invention is providing a refueling assembly with structure for draining liquids away from the filler tube end and out of a chamber surrounding the filler tube end, and which is simple in operation and inexpensive to manufacture and install.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.